Column placement involves the physical disposition of a column—typically concrete—in or proximate to the ground for supporting associated structure. Columns often support bridges, roadways, platforms and walls, to name but a few associated structures. Given the massive weight of many associated structures supported by columns, precision in the placement of the columns can be critical to ensure the integrity of the associated structures. Moreover, given the sheer manpower required to place columns and associated structure, misplacement of a column can result in substantial cost overruns. In the modem world of razor-slim margins in civil works project management, cost overruns can be intolerable and can form the difference between a loss on a project and profitability.
Conventional column placement generally involves the lifting of a pre-cast column by a crane to a position above a drill hole. Several workers can subsequently guide the hovering column down and into the hole where the column can be secured by temporary scaffolding. Recognizing the imprecise nature of this exercise, many skilled artisans prefer the use of a template in placing the column. A template generally includes a scaffold-like arrangement of wooden or metal bars configured to support the placement of a column in or above a hole. Ordinarily, the template can be placed such that an opening in the template can align with a hole in the ground, A column can be lowered by crane and guided through the hole into the ground. Still, given the mass of a typical column, many works are required to position and support the column in the hole.
FIG. 1 illustrates a typical template arrangement, such as a “Hubbard” arrangement. A typical template arrangement includes a template body 120 supported over a hole 130 in the ground 140 by one or more template feet 160. A column 110 can be lowered through the template body 120 into the hole 130 and secured in place by one or more adjustable straps 150 such as “come-alongs” as is known in the art. Notably, the adjustable straps 150 can be coupled to the template body 120 and tightened individually so as to cause the column 110 to stand as close to vertical as possible without unduly leaning to any one side.
It will be apparent to the skilled artisan, however, that controlling the vertical placement of the column 110 through the use of multiple individually adjustable straps 150 can be resource intensive and quite difficult given the number of control points dictating the vertical placement of the column and the distance between each control point. Moreover, the mass of the column 110 often can cause shifting in the placement of the template body 120 in respect to the hole given the free-floating nature of the template feet 160. Accordingly, substantial imprecision can result.
The skilled artisan further will recognize several other deficiencies associated with the conventional column placement template. Most notably, only a single column can be placed at any one time. Also, once a column has been placed and has been secured in the hole in the ground, placing the next column may require alignment with the previously set column. Preserving the accuracy of placement of a new column relative to an existing column can introduce an entirely new set of difficulties. Additionally, the process of auger-cast drilling a hole prior to the placement of a column through the template, and the subsequent dismantling of the template once the column has set in order to remove the template can result in substantial time and manpower consumption. Thus, a more efficient template for placing columns would be desirable.